PHENYLALANINE AMMONIA-LYASE 1 (PAL1) EXPRESSION DURING COLD STRESS IN TWO JAPANESE TOMATO VARIETIES
by Naoya Kobayashi
Abstract – Cold stress is one of the most important and deleterious stresses for Solanum lycopersicum (tomatoes) during their growth, causing enzymatic browning, stunted growth or, in severe cases, death. Phenylalanine Ammonia-lyase 1 (PAL1) is known to be induced during cold stress in several species of plants, but the specific role of PAL1 is still unknown. Some tomato varieties are more cold tolerant than the others, which may be in part due to PAL1 expression. In this study, our goal is to observe whether PAL1 expression varies between tomato cultivars available in Japan. Using semi-quantitative RT-PCR, PAL1 expression in both Fruitica and Momotaro cultivars was compared. The percent change between the control and treatment of both varieties was surprisingly not statistically different. The results show that both varieties are not significantly different in terms of PAL1 expression. Better understanding of cold stress tolerance genes in tomatoes can help farmers decide which varieties to buy in an ever-changing climate.